Parts Per Billion (ppb)
Parts Per Billion (ppb) is a measurement term used to describe the number/ concentration of particular gas, liquid, or solid mixture. Ppb is one part of a chemical found in one billion (1,000,000,000) parts.
- Measured in water or gas: one microgram per litre (ug/l)
- Measured in solid material: microgram per kilogram of for example soil (ug/kg)